Multi-pronged Strings Research Articles

T -branes, string junctions, and 6D SCFTs

Recent work on 6D superconformal field theories (SCFTs) has established an intricate correspondence between certain Higgs branch deformations and nilpotent orbits of flavor symmetry algebras associated with T-branes. In this paper, we return to the stringy origin of these theories and show that many aspects of these deformations can be understood in terms of simple combinatorial data associated with multi-pronged strings stretched between stacks of intersecting 7-branes in F-theory. This data lets us determine the full structure of the nilpotent cone for each semi-simple flavor symmetry algebra, and it further allows us to characterize symmetry breaking patterns in quiver-like theories with classical gauge groups. An especially helpful feature of this analysis is that it extends to "short quivers" in which the breaking patterns from different flavor symmetry factors are correlated.

Supersymmetric quantum mechanical description of four dimensional black holes

By assuming the existence of a novel multipronged string state for D-particles interacting with D-brane intersections in type IIA string theory, we are able to derive a quantum mechanical description of supersymmetric Reissner-Nordstrom black holes. A supersymmetric index calculation provides evidence for this conjecture. The quantum mechanical system becomes two decoupled conformal quantum mechanical systems in the low energy limit. The conformal quantum mechanics has expected properties of a dual description of string theory on $AdS_2\times S^2$.

Moduli space dimensions of multipronged strings

The numbers of bosonic and fermionic zero modes of multipronged strings are counted in $\mathcal{N}=4$ super-Yang-Mills theory and compared with those of the type IIB string theory. We obtain nice agreement for the fermionic zero modes, while our result for the bosonic zero modes differs from that obtained in the type IIB string theory. The possible origin of the discrepancy is discussed.

Massless monopoles and multi-pronged strings

We investigate the role of massless magnetic monopoles in the N=4 supersymmetric Yang-Mills Higgs theories. They can appear naturally in the 1/4-BPS dyonic configurations associated with multi-pronged string configurations. Massless magnetic monopoles can carry nonabelian electric charge when their associated gauge symmetry is unbroken. Surprisingly, massless monopoles can also appear even when the gauge symmetry is broken to abelian subgroups.

M-Theory Description of 1/4 BPS States in N = 4 Supersymmetric Yang-Mills Theory

We discuss BPS states preserving 1/4 supersymmetries of N=4 supersymmetric Yang-Mills theory as M2-branes holomorphically embedded and ending on M5-branes. We use techniques in electrodynamics to find the M2-brane configurations, and give some explicit examples. In case the M2-brane worldsheet has handles, the worldsheet moduli of the M2-brane is constrained in a discrete manner. Several aspects of multi-pronged strings in type IIB string theory are beautifully reproduced in the M-theory description. We also discuss the relation between the above construction and the D2-brane dynamics in type IIA string theory.

Multi-pronged String and BPS Saturated Solutions in N=4 SU(N) Super Yang-Mills Theory

Multi-pronged String and BPS Saturated Solutions in N=4 SU(N) Super Yang-Mills Theory

Multi-pronged strings and BPS saturated solutions in SU(N) supersymmetric Yang-Mills theory

Extending our previous work on SU(3), we construct spherically symmetric BPS saturated regular configurations of N = 4 SU( N) supersymmetric Yang-Mills theory preserving 1 4 supersymmetry, and investigate their features. We also give exact solutions in the case some of the free parameters of the general solutions take certain values. These field theory BPS states correspond to the string theory BPS states of multi-pronged strings connecting N different D3-branes by regarding the N = 4 supersymmetric Yang-Mills theory as an effective field theory on parallel D3-branes. We compare our solutions with multi-pronged strings in the string picture.

String junctions and BPS states in Seiberg-Witten theory

We argue that certain BPS states in the D3-brane probe realization of N = 2 SU(2) Super-Yang-Mills theory correspond to multi-pronged strings connecting the D3-brane to the background 7-branes. This provides a physical realization of the decay of these states on the curve of marginal stability, and explains their absence in the strong coupling regime.

Exceptional groups from open strings

We consider type IIB theory compactified on a two-sphere in the presence of mutually non-local 7-branes. The BPS states associated with the gauge vectors of exceptional groups are seen to arise from open strings connecting the 7-branes, and multi-pronged open strings capable of ending on more than two 7-branes. These multi-pronged strings are built from open string junctions that arise naturally when strings cross 7-branes. The different string configurations can be multiplied as traditional open strings, and are shown to generate the structure of exceptional groups.